Currently, in a Long Term Evolution (LTE) system, user equipment (UE) detects downlink control information (DCI) in a downlink subframe. The DCI includes scheduling information used by the UE to send a physical uplink shared channel PUSCH and scheduling information used by the UE to receive a physical downlink shared channel (PDSCH), for example, a quantity of physical resource blocks used in a frequency domain, a used modulation and coding scheme or modulation scheme, and a quantity of bits included in a carried transport block. The PUSCH mainly carries uplink data sent by a terminal, and is sent by using a format of single carrier frequency division multiple access (SC-FDMA). A smallest scheduling granularity in the frequency domain is one physical resource block (PRB), one PRB includes 12 orthogonal subcarriers in the frequency domain, and a subcarrier spacing is 15 kHz. Therefore, one PRB includes a 180-kHz frequency resource.
However, with rapid development of communications technologies, a plurality of types of LTE terminals are already available or one type of terminal may have a plurality of capabilities. For example, a first-type terminal can send a single subcarrier with a 3.75-kHz orthogonal subcarrier spacing by means of SC-FDMA in an uplink manner, or send a single sub-channel with a 3.75-kHz sub-channel bandwidth by means of FDMA in an uplink manner; a second-type terminal or a first-type terminal has a capability of sending a single subcarrier with a 15-kHz orthogonal subcarrier spacing by means of SC-FDMA in an uplink manner; and a third-type terminal or a first-type terminal has a capability of sending a plurality of subcarriers with a 15-kHz orthogonal subcarrier spacing by means of SC-FDMA in an uplink manner. The three types of terminals all support an orthogonal frequency division multiple access (OFDMA) technology in downlink, and a subcarrier spacing is 15 kHz.
However, because a smallest scheduling granularity of the LTE system is one PRB, and granularity scheduling of a single subcarrier or a plurality of subcarriers is not supported, none of the three types of terminals can be supported in the existing LTE system. For example, if the first-type terminal sends a signal over a single subcarrier with a 3.75-kHz subcarrier spacing or a single sub-channel with a 3.75-kHz sub-channel bandwidth, a length of the signal in a time domain is at least four times of a length of a signal sent over a 15-kHz single subcarrier. A frame structure in the LTE system is designed according to a 15-kHz subcarrier spacing. Therefore, the first-type terminal is not supported. Therefore, a scheduling method, a data transmission method, and an apparatus are urgently required.